COM dll注册时收到错误80004005

Question

I have a Delphi COM dll which works perfectly on several machines. However when I try to register it on one Windows 7 box I get the following error

DllRegisterServer failed with error code 0x80004005

I have tried the obvious solutions around ensuring that the correct supporting libraries are registered.

Answer 1

The solution which I found here was to elevate the call to regsvr32

Running CMD as administrator and then calling regsvr32 from the command line solved my immediate issue, but didn't track down the main bug.

Answer 2

That error code is E_FAIL which is the generic COM error code. It means, something went wrong, but we aren't going to be any more specific than that .

So, what did go wrong? Well, you have the COM server, and we don't. So you can debug it to find out. Build the COM server with debug enabled, and debug DCUs for the RTL files too since you'll want to debug them perhaps.

You'll want to debug the code that responds to registration. That's the TComServer.UpdateRegistry method. That code in turn calls registration methods on the various class factories that you declared. The failure could be in your registration code, or the default registration code. You need to debug the execution of the registration code. Do that by using regsvr32 as your host process. Set a break point at the start of UpdateRegistry , and then debug to work out what the problem is.

I can see that by trial and error you have discovered that your COM server needs to be registered with admin rights, presumably because it writes to HKLM. There's no way that, given your question, that information could have been discerned. And so I wrote this generic answer to show how to debug and diagnose such a general problem.